This paper outlines the impacts of ignoring the costs to the community of increased rural waterlogging and salinity. It identifies the cost of no further action, and the costs and benefits of undertaking a land and water management plan. The processes of developing and evaluating the plan are explained. Difficulties in obtaining data, both for the community and the economist, are discussed. Data availability then shapes the range of costs and benefits that can be evaluated. The paper looks at the process and results of a case study of a Land and Water Management Plan for an irrigation district in central New South Wales. The case study demonstrated all the complexities of community and professional conflict, difficulties in data availability, budget and time constraints and a rigorous review process. Also discussed are the implications of recommendations of this Land and Water Management Plan Economic Evaluation for the community and government.